"Some issues with my groin have made things tough since the game against BATE in the Europa League in February and now they have forced me to stop training altogether.

"After various medical consultations, the conclusion has been reached that I cannot keep on pushing it and I have started a period of treatment that cannot be done alongside competitive football.

"I am sorry that all of the effort and sacrifice made to come to Arsenal hasn't come to fruition as hoped and you can't even imagine how angry I am about it, but health comes first.

"I want to give my thanks again to such a big club for trusting in me, although things haven't gone as we pictured they would.

"I am stepping aside but I am grateful for the messages of care and support that you all have sent to me every day. This will be where I take my strength from in order to return stronger than ever and even more determined."